Balance the reaction: c5h90 + 02 = c02 + h20

When you balance a reaction, you want the same number of atoms of each element on both sides of the arrow/in the reactants (left side) and products (right side). For example, if there are four oxygen on the left, you want four oxygen on the right and if there are three hydrogen on the left, you want three hydrogen on the right, etc.

So your equation is:


On the left, you have 5 carbon, 9 hydrogen, and 3 oxygen.
On the right, you have 1 carbon, 2 hydrogen, and 3 oxygen.

You want the same numbers of each on both sides. To do this you have to multiply the compounds by adding numbers to the front of them. You can never add subscripts. Most of the time, you are reasonably guessing and checking to see which numbers work, concentrating on one element at a time.

I balanced the H's first, since there are 9 on the left and 2 on the right. You want a number that is a multiple of both. I tried 18 at first, meaning  had to be multiplied by 2 and  by 9. However, I ran into trouble with the O's because that meant I would end up with an even number of O's on the left, no matter what I multiplied  by, and an odd number of O's on the right.

That meant I would have to use 36 as my next least common multiple of 9 and 2, giving a coefficient of 4 and  a coefficient of 18. Everything else balanced out from there. There were 20 C's on the right because of  (from the left). And  had a coefficent of 27 because there were already 4 on the left, and 58 on the right, so 58-4 = 57, divided by 2 (2 oxygen atoms in ) = 27. 

The final equation was:

assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

explanation

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.